When I have a Linux desktop (Ubuntu/gnome in this case but I'm guessing this is a more general problem) that freezes/hangs in a way that I still have the ability to switch to another tty with ctrl+alt+F1..12, how can I regain access to the [GUI] applications still running in that unresponsive X session on tty7?
I've encountered variations of this problem over my brief but ongoing experience with Linux, the most recent and frustrating was after trying to load a "Guest session" (clicking through the user switcher at the top right panel). The session failed to load leaving nothing but a mouse cursor on a white background. Notification sounds continued to play from my original login, including incoming IM messages. I was able to start a new session from tty2 with startx -- :2.
Is there a way to do one or more of the following (in order of preference): A) Pull those running applications over to the new X screen? B) Send some sort of signal to unfreeze the original X screen (something like ctrl+alt+backspace but that would actually preserve the running programs)? C) Send a signal that would tell all running programs to save data before exiting?
When faced with a similar situation in Windows I can usually recover with ctrl+alt+delete, Task Manager and/or Log Out (even the most stubbornly locked programs will sometimes snap out of it and offer a "Save before exit?" prompt when Windows signals an impending log out). With Linux, I'm a bit lost as where to start. Please note I'm not really asking for a diagnosis of this particular white screen hang; maybe the best question to sum it all up is:
"What is your recovery checklist when a gnome desktop session goes bad?"
